Apparatus for making conical diaphragms



Se t. 192

p 7 c. L. FARRAND ET AL APPARATUS FOR MAKING CONICAL DIAPHRAGMS Filed Nov. 5, 1926 ATTORNEYS,

Patented Sept. 6, 1927.

UNITED STATES PATENT OFFICE.

CLAIR L. FARRAND,- OF FOREST HILLS, NEW YORK, AND ERNEST ROSS, OE-EAST ORANGE, NEW JERSEY; SAID ROSS ASSIGNOR TO FARRAND MFG. CO. INC., OF LONG ISLAND CITY, NEW YORK, A CORPORATION OJ? NEW JERSEY.

APPARATUS FOR MAKING CONICAL DIAPHRAGMS.

Applloation filed lztovember 5, 1926. Serial Noel-18.854.

This invention relates to the manufacture of so called double-cone diaphragms for loud speakers.

Many of the radio loud speakers now in use have a paper diaphragm formed bycement'ing together the base edges of two cones, or a cone and a cone frustum. ThlS type of diaphragm is usually referred to as a double-cone diaphragm.

One object of this invention is to provide a simple piece of apparatus which facilitates the assembling and uniting of. the two sections of a double-cone diaphragm.

Another object is to provide an improved process of assembling or uniting the two sections of a double-cone diaphragm.-

In the type of double-cone diaphragm with which this invention particularly deals, the edges of the cone sections are not cemented directly to each other but-a narrow ring, whose axis is parallel with the cone axis, is interposed between the edges in such a way that the edge ortion of each cone section extends slight y beyond the ring to form a peripheral groove which is later filled with an ornamental filler such as a twisted cord or the like.

The apparatus by which the cone sections are assembled and united comprises a group of holding devices "for receivin the cone sections and the above-mentione ring and holding them in proper relation while they are being cemented together andwwhile they are being dried.

' The accomp'anyin drawing illustrates the improved process 0 assembling or uniting the cone sections and also illustrates one form of apparatus in which the process may be carried out.

In the drawing:

Fig. 1 is a top plan view of the apparatus;

Fig. 2 is a vertical section taken on the line 22 of Fig. 1;

Fig. 3 is an enlarged partial vertical section showing the upper ring partly removed;

Fig. 4 is a detail perspective view of the split ring that is utilized to facilitate the leaves the apparatus; and

r Fig. 6 is a partial vertical section of the diaphragm showing the ornamental cord applied to the groove at the peripheryof the diaphragm.

The description of the apparatus and the purpose of its various parts will be more readily understood if theconstruction of the diaphragm is firstexplained. Fig. 2 shows the general shape of the double-cone-diaphragm. It comprises a cone section 1 and a frusto-conical section 2. Fig. 5 more clearly shows the construction at the meeting edges of the cone and cone frustum. A relatively narrow ring 3 which may be made of heavy paper or card board has its axis parallel with the axis of'the cone and cone frustum, and is cemented to bothsectionsof the diaphragm by the adhesive represented at 4. The ring 3 is spaced back as ight distance from the extreme edges of the cone and cone frustum so as to form a' peripheral groove 5 which is intended to receive an or-- namental filler such as 'a twisted cord as shown at .6 in Fig. 6. The cord conceals'the joint between the two sections of the diaphragm and adds to the ornamental appearance of the finished diaphragm.

The apparatus in which the cone'sections are united comprises a lower ring 7 Sn ported on a suitable table 8 by means of t e le 9. Thering -7 has-a beveled seat 10 a apted to accommodate the edge portion of the cone section -1. A second continuous rmg 11 is adapted to be ositioned on and 7 removed from the ring 7 y means of handles 12. The ringl 11 also has a beveled under surface 13 t the same as the inclination of the cone frustum 2. A ring 14, split at 15 is adapted to be contracted by a handle 16. a ainst a shoulder 17 formed on the ring 7. The ring 11 is adapted to nest within the ring 14. When the ring 11 is in place it is adapted to e inclination of which is be pressed downwardly toward the ring 7 by a plurality of hand clamps each of which comprises an angle member 18, the vertical leg of which is adapted to rest on the ring 7, and the horizontal leg of which is adapted to project over the ring 11. Each clamp has a pin 19 which is rigidly attached at its lower end to the ring 7 and which passes at its upper end loosely through the horizontal portion of the angle 18.- A nut 20 is threaded on the upper end of each pin 19 and may be turned by handles 21. It will now be noted that the angles18 may be turned so that the horizontal portions either clear the ring 11 or project over it. When it is desired to clamp the ring 11 in place the angles are turned so that their horizontal portions project over the ring 11, then the nuts 20 are turned to force the angles down against the ring 11. A spring 22 preferably encircles each pin 19 and reacts at its lower end against the ring 7 andat its upper end against the angle" 18 so as to yieldingly hold the horizontal portion of the angle in a raised position.

A heating coil 23 is clamped to the lower surface of the ring 7 by means of clamps 24. A suitable heating medium such as steam or hot water may be supplied to the coil at 25 and discharged at 26.

The diaphragm sections are assembled and united in the apparatus as follows. The cone 1 and the frustum 2 previously receive their shape either by hand or in a suitable machine. The ring 11 is removed and the split ring-14 is loosened. The cone 1 is then positioned in the ring 7 as shown in Figs. 2 and 3 after which'a temporary expansible metal ring 27, shown in Fig. 4', is placed around the edge of the cone 1 and against the inner surface of the ring 14. a

of double-cone diaphragms comprising two,

The cardboard ring 3, preferably in two or more sections, is then positioned against the inner surface of the ring 27. The cone frustum 2 is next positioned so that its edge overlaps the upper edges of the metal ringl 27 and cardboard ring 3. The ring 11 is t en positioned within the ring 14 so that it rests upon the entire diaphragm structure. The handle 16 is then turned to contact the ring 14 and the ring 11 is clamped down by means of the angles 18. The operator now takes-a brush, dips it in adhesive such as liquid celluloid and reachesin the interior of the diaphragm. lVith a circular motion he paints the adhesive against the inner surface of the carboard ring 3 and against the adjacent inner surfaces of the cone and cone frustum. The adhesive penetrates into the crevices between the ring 3 and the diaphragm sections as shown in Fig. 5. The diaphragm is allowed to remain in the apparatus until the heat from the coil 23 sets, or at least partially sets the adhesive, after which the ring 14 is loosened, the ring the set adhesive thus-uniting the cone 1, the

frustum 2 and the ring 3 into a unitary structure. It will be understood of course. that the ring 27 is really part'of the ap paratus and is used over and over again.-

The metal ring 27 and the carboard ring 3 are of such relativewidths that when the ring 11 is clamped in place the metal ring 27 prevents the cardboard ring 3 and the diaphragm sections from being crushed but at the same time it allows the edges of the diaphragm sections to be pressed into close contact with the upper and lower edges of the cardboard ring 3. The ring 27 not only acts-as a stop to properly space the ring 11 with respect to the ring 7 and thereby prevent the diaphragm parts from being inured, but it also acts as a spacer to properly space the cardboard strip 3 in such a way that when the ring27 is removed a recess or groove the size of the ring remains in its place at the periphery of the diaphragm.

The metal ring 27 and cardboard ring 3 are of such a size that the peripheral groove 5, which finally exists at the periphery of the. diaphragm is the proper size to receive the cord 6. The cord may be positioned in the groove 5 wholly by hand or by a suitable machine and may be held in place by adhesive represented at 28. The diaphragm structure itself is covered in other copending applications.

We claim:

1. Apparatus for use in the manufacture members at least one of which is removable with respect to the other, each of said members having a beveled surface forming between them an annular opening converging towards its periphery .for accommodating the angular edge portion of the double-cone diaphragm, and means for supplying heat to the diaphragm parts while held between said members.

2. Apparatus for use in the manufacture of double-cone'diaphragm's comprising two membersat least one of which is removable with respect to theother, each of said members having a beveledsurface forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the double-cone diaphragm, and means associated with at least one of said members for heating the same.

3. Apparatus for use in the manufacture of double-cone diaphragms comprising two members at least one of which is removable with respect to the other, each of said members having a beveled surface forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the doublecone diaphragm, and means for detachably clamping said members together.

4. Apparatus for use in the manufacture of double-cone diaphragms comprising two rings at least one of which is removable with respect to the other, each of said rings having a beveled surface forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the double-cone diaphragm, and a third ring encircling at least a part of each of the first mentioned rings.

5. A paratus for use in the manufacture of dou le-cone diaphragms comprising two rings at least one of which is removable with respect to the other, each of said rings having a beveled surface forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the double-cone diaphragm, a split ring encircling at least a part of each of the first mentioned rings, and means to contract said ring.

6. Apparatus for use in the manufacture of double-cone diaphragms comprising a lower ring, an upper ring, said rings having beveled surfaces forming between them an annular opening converging towards its eriphery for accommodating the angular e ge portion of the double-cone diaphragm, a third ring encircling at least a part of each of the first mentioned rings, and a plurality of clamps for clamping the upper rin to the lower ring with the edge portion 0 the diaphragm inter osed between them.

7. Apparatus or use in the manufacture of double-cone diaphragms comprising a lower ring, an upper ring, said rings having beveled surfaces forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the double-cone diaphragm, a thirdsplit ring encircling at least a part of each of the first mentioned rings, means for contracting said third ring, and a plurality of clamps for clamping the upper ring to the lower ring with the edge portion of the diaphragm interposed between them.

8. Apparatus for use in the manufacture of double-cone dlaphragms comprising a lower ring, an upper ring, said rings having beveled surfaces forming between them an annular opening converging towards its eriphery for accommodating the angular e ge portion of the double-cone diaphragm, said lower ring having an annular shoulder immediately below the upper edge of its beveled surface, a third split ring encircling at.

least a part of each of the first mentioned rings, and means to contract said third ring against said shoulder.

9. Apparatus for, use in the manufacture of double-cone diaphragms comprising a lower ring, an upper ring, said rings having beveled surfaces forming between them an annular opening converging towards its periphery for accommodating the angular edge portion of the double-cone diaphragm, said lower ring having an annular shoulder immediately below the upper edge of its beveled surface, a third split ring encircling at least a part of each of the first mentioned rings, means to contract said third ring against said shoulder, a plurality of clamps for clamping the upper ring to the lower ring with the angular edge portion of the double-cone diaphragm interposed between them, and means for appl ing heat to the parts of the diaphragm while clamped between the rings.

10. The process of assembling and uniting the sections of a double-cone diaphragm which comprises placing a temporary ring between the extreme base edges of the sections, positioning a permanent ring between the sections at the inner side of the temporary ring, cementing the permanent ring to the diaphragm sections and thereafter removing the temporary ring.

11. The process of assembling and uniting the sections of a double-cone diaphragm which comprises placing a temporary ring between the extreme base edges of the sections, positioning a permanent ring between the sections at the inner side of the temporary ring, cementing the permanent ring to the diaphragm sections, applying heat to the diaphragm sections and said permanent ring, and thereafter removing said temporary ring.

12. The process of assembling and uniting the sections of a double-cone diaphragm which comprises placing a temporary ring between the extreme base edges of the sections, positioning a permanent ring between the sections at the inner side of the temporarv ring, cementing the permanent ring to the diaphragm sections, applying pressure to the peripheral portions of the diaphragm sections axially of said rings, and thereafter removing said temporary ring.

13. The process of assembling and uniting the sections of a double-cone diaphragm which comprises placing a temporary ring between the extreme base edges of the sections, positioning a permanent ring between the sections at the inner side of the temporary ring, cementing the permanent ring to the diaphragm sections, applying ressure to the peripheral portions of the iaphragm sections axially of said rings while confining the temporary ring so that it will not move radially outward, applying heat to the diaphragm sections and said permanent ring, and thereafter removing said temporary ring.

14. The process of assembling and uniting the sections of a double-cone diaphragm which comprises placing a temporary ring between the extreme base edges of the sections, positioning a permanent ring between the sections at the inner side of the temporary rin cementing the permanent to 10 the diap ragm sections, thereafter removing the temporary ring and positionin a permanent filler in the groove formed y the removal of the temporary ring.

In testimony whereof we aflix our signa- 15 tnres.

CLAIR L. FARRAND. ERNEST ROSS. 

